Tammy left home at 11.25 a.m. and drove towards the seaside resort. 2 hours later, her cousin left their home and drove towards the same seaside resort at 88 km/h. When the cousin reached the seaside resort at 4.25 p.m., Tammy had another 3 km to travel. What was Tammy’s average speed? Express your answer in mixed number.
Time that the Tammy's cousin started driving = 1.25 p.m.
Duration that Tammy's cousin drove from 1.25 p.m. to 4.25 p.m. = 3 h

Distance that Tammy's cousin travelled
= 3 x 88
= 264 km

Distance that Tammy travelled by the time her cousin reached the city
= 264 - 3
= 261 km

Time that Tammy took to travel 261 km = 5 h

Tammy's average speed
= 261 ÷ 5
= 52¹₅ km/h

Answer(s): 52¹₅ km/h